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<div class="titlepage"><div><div><h3 class="title">
<a name="fiber.callbacks.success_or_exception"></a><a class="link" href="success_or_exception.html" title="Success or Exception">Success or Exception</a>
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<p>
        A wrapper more aligned with modern C++ practice would use an exception, rather
        than an <code class="computeroutput"><span class="identifier">errorcode</span></code>, to communicate
        failure to its caller. This is straightforward to code in terms of <code class="computeroutput"><span class="identifier">write_ec</span><span class="special">()</span></code>:
      </p>
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<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">write</span><span class="special">(</span> <span class="identifier">AsyncAPI</span> <span class="special">&amp;</span> <span class="identifier">api</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">data</span><span class="special">)</span> <span class="special">{</span>
    <span class="identifier">AsyncAPI</span><span class="special">::</span><span class="identifier">errorcode</span> <span class="identifier">ec</span> <span class="special">=</span> <span class="identifier">write_ec</span><span class="special">(</span> <span class="identifier">api</span><span class="special">,</span> <span class="identifier">data</span><span class="special">);</span>
    <span class="keyword">if</span> <span class="special">(</span> <span class="identifier">ec</span><span class="special">)</span> <span class="special">{</span>
        <span class="keyword">throw</span> <span class="identifier">make_exception</span><span class="special">(</span><span class="string">"write"</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span>
    <span class="special">}</span>
<span class="special">}</span>
</pre>
<p>
      </p>
<p>
        The point is that since each fiber has its own stack, you need not repeat
        messy boilerplate: normal encapsulation works.
      </p>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2013 Oliver Kowalke<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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